新型双纤芯大模场光纤传感特性研究

Research on the characteristics of a novel large mode area fiber with double core

为了提高有效模场面积,降低光纤中光功率密度,减小非线性效应,提出了一种杂化石墨烯-金属等离子体传感薄膜双芯光纤,可应用在等离子体波导生物传感器。侧面抛光纤维的横截面包含有两个折射率n_(1)=1.4478的均匀纤芯,抛光面上涂覆30 nm金膜。金膜进一步涂覆有0.34 nm的石墨烯层。通过对双芯光纤的有效模式指数,泄漏损耗和有效模场面积的研究,证实了单层石墨烯对电介质的变化提供了最佳的灵敏度。实验结果表明基本纤芯模LP_(01)模的有效模场面积增长速率比高阶纤芯模式LP^(11)模的增长速率要快,并且当纤芯折射率是1.4460,波长为600 nm时,基模的有效模场面积为275μm^(2),大于同等条件下其他的纤芯折射率值时的有效模场面积,取得了大模场模式,能减小光纤的非线性效应。在医疗设备、激光武器、遥感测控、光纤通信等重要领域都有着广泛的应用前景。

In order to improve the effective mode field area,reduce the optical power density and reduce the nonlinear effect in the fiber,a graphene-metal plasma double core sensor is proposed,which can be applied to a plasma waveguide biosensor.The cross section of the side polished fiber contains two cores with refractive index n_(1)=1.4478,and the polished surface is coated with 30 nm gold film.The gold film is coated with a 0.34 nm graphene layer.Through the study of effective mode index,leakage loss and effective mode field area of the dual-core fiber,it is confirmed that the monolayer graphene provides the best sensitivity to dielectric changes.The experimental results show that the effective mode area growth rate of the basic core mold LP_(01) is faster than that of the high-order core mode LP_(11),and when the core refractive is 1.4460,the wavelength is 600 nm,the effective mode area of the base mode is 275μm^(2),which is greater than those of other core refractive values under the same conditions.The large mode area is obtained,and the nonlinear effect is reduced.In medical equipments,laser weapons,remote measurement and control,optical fiber communication and other important fields have a broad application prospect.